1. Field of the Invention
This invention relates to sprinklers and more particularly to sprinkler heads having self-contained tools attached thereto for facilitating the assembly or disassembly of a similar rotary head sprinkler.
2. Description of the Prior Art
Rotary sprinklers, especially the impulse type step-by-step rotary sprinklers have become a common and necessary implement for providing man-made irrigation for citrus groves and other agricultural crops. In citrus tree groves the sprinkler heads are normally carried on pipes rising to a high elevation above the trees. Due to normal weather cycles the utilization of these rotary sprinklers is quite sporadic. During the rainy season the sprinklers are seldom used, while during the dry season the sprinklers are utilized almost continuously. During the periods of infrequent use, it is often desirable to inspect and repair any defective sprinklers which may provide problems at a subsequent time. Also, during periods of heavy utilization the sprinklers have a higher probability of failing due to the heavy use. When such a failure occurs, the failed unit must be promptly replaced. It is therefore highly desirable to provide a rotary sprinkler head having a large mean time between failure (mtbf), and furthermore to provide a rotary sprinkler head which may be easily disassembled, repaired and then rapidly re-assembled and returned to irrigation service.
Prior art sprinklers have commonly utilized one of two common techniques to facilitate the rapid disassembly of the sprinkler head, which requires the removal of the spindle shaft as it communicates through the sprinkler swivel and into the sprinkler head. The first prior art method includes a hex-nut shaped coupling on the end of the spindle which protrudes into the riser pipe. This hex-nut shaped coupling is removed by the use of a spanner or closed end wrench. The second method utilized in the prior art is to include a transverse channel in the lower end of the spindle which then may be engaged by a large screw driver type blade. Both of these prior art methods require that the lower end of the sprinkler spindle be extended a considerable distance beyond the sealing washers and wear washers which are coupled between the end of the spindle and the swivel. This extension of the first end of the sprinkler spindle is required to produce a sufficiently strong spindle structure, while at the same time providing a sufficient clearance between the coupling means and the sealing and wear washer assemblies. Costa et al in U.S. Pat. No. 3,764,073 discloses a rotary sprinkler head utilizing a previously discussed transverse channel method of decoupling the spindle from the sprinkler head and the swivel assembly.
However, both of these previously described methods require a longitudinally extended spindle end for providing the necessary material to strengthen the coupling at the distended end thereof. This longitudinal extension protrudes into the riser pipe and, as shown in the Costa U.S. Pat. No. 3,764,073, severely reduces the clearance between the enlarged cavity at the distended end of the riser pipe and the swivel. This reduced clearance allows dirt, mud, and other particulate matter suspended in the irrigation water to accumulate between the swivel and the riser pipe, thereby substantially increasing the probability of jamming the rotary motion of the spindle and therefore the rotary motion of the step-by-step sprinkler head.
Other sprinkler head designs are disclosed by Senninger in U.S. Pat. No. 3,669,356 and the references contained therein.